Organotin stabilizer composition containing more than 18% tin and resin compositions containing the same

ABSTRACT

A POLYVINYL CHLORIDE RESIN STABILIZER IS PROVIDED HAVING A HIGH CONCENTRATION OF TIN, IN THE RANGE FROM ABOUT 18 TO ABOUT 35% BY WEIGHT, AND A HIGH CONCENTRATION OF SULFUR, WITHIN THE RANGE FROM ABOUT 10 TO ABOUT 25% SULFUR, COMPRISING AT LEAST ONE ORGANOTIN ALPHA-OR BETAMERCAPTO CARBOXYLIC ACID ESTER SULFIDE, AND PREFERABLY MIXED MONOORGANOTIN AND DIORGANTIN ALPHA-OR BETAMERCAPTO CARBOXYLIC ACID ESTER SULFIDES. POLYVINYL CHLORIDE RESIN COMPOSITIONS ARW ALSO PROVIDED, CONTAINING THESE STABILIZERS.

United States Patent 3,817,915 Patented June 18, 1974 3,817,915ORGANOTIN STABILIZER COMPOSITION CON- TAIN'ING MORE THAN 18% TIN ANDRESIN COMPOSITIONS CONTAINING THE SAME Otto S. Kauder, Jamaica, and MarkW. Pollock, Teaneck,

19.1., assiguors to Argus Chemical Corporation, Brookyn, N.Y.

No Drawing. Original application Dec. 19, 1967, Ser. No. 691,866, newPatent No. 3,565,930, dated Feb. 23,

1971. Dividedand this application Apr. 14, 1970, Ser. No. 32,502

- :Intt'Cl. (10815 45/62 US. Cl. 26045.75 K 33 Claims ABSTRACT OF THEDISCLOSURE A polyvinyl chloride resin stabilizer is provided having ahigh concentration of tin, in the range from about 18 to about 35% byweight, and a high concentration of sulfur, within-the range from about10 to about 25% sulfur, comprising at least one organotin alphaorbetamercapto carboxylic acidester sulfide, and preferably mixedmonoorganotin and diorganotin alphaor betamercapto carboxyli'c'acidester sulfides.

Polyvinyl chloride resin compositions are also provided, containingthese stabilizers.

This application is a 'division' of'Ser. No. 691,866, filed Dec. 19,1967, now U.S.Pat. No.3,565,930, dated Feb. 23, 1971. A

This invention relates to a stabilizer composition for polyvinylchloride resins "and to polyvinyl chloride resin compositions havingimproved resistance to deterioration at 350 F. and more particularly, toa stabilizer composition comprising at least-one organotin mercaptocarboxylic acid ester sulfide having a high concentration of tin, and topolyvinyl chloride resin compositions containing such stabilizers.

The stabilizing effectiveness of organotin stabilizers for polyvinylchloride resins is generally associated with or- "ganotin groups, tincontent, and, to some degree, sulfur content. The higher therelative'proportion of these, the more elfective the organotin compoundusually is as a stabilizer.=I-Io'we'ver,"thereare exceptions to the rulethat make prediction fallible.

The organotin sulfides, for example, ofier the highest tin and'sulfurcontents per organotin group, and yet they are not'the beststa'bilizers, and have never found a place as acomnier'cial stabilizer,affording, among other things, a poor initial color. Despite theirconsiderably lower tin and' sulfur contents, the most effectiveorganotin stabilizers'pre'sently in use, and the recognized standard forjudging other organotin stabilizers, are the organotin mercapto'carboxylic acid estersylhe great majority'of these materials,andcrtainly all of the niost commonly used commercial products, areeither liquid at room tempera- The use of the organotin mercaptocarboxylic acid esters as stabilizers for polyvinyl chloride resins iswell known, and is generally set forth in such early patents as US.Pats. Nos. 2,753,325 to Leistner et al., issued June 26, 1956, 2,641,596to Leistener et al., issued June 9, 1953, and 2,648,650 to Weinberg etal., issued Aug. 11, 1953. v

The organotin sulfides are described in US. Pat. No. 2,746,946 toWeinberg et al., dated May 22, 1956. Polymeric organotin sulfides havinga high proportion of tin and sulfur by weight have also been suggested.Examples of such materials are given in US. Pat. 3,021,302 to Frey,dated Feb. 13, 1962, which discloses polymeric condensation products ofhydrocarbon stannoic acid, hydrocarbon thiostannoic acid andco-condensation products of these materials. However, all of thesematerials have sulfered from one or another failing, which until now hasprevented their coming into general commercial use.

Dutch patent specification No. 6700014, published July 4, 1967, andreferring to US. applications Ser. Nos. 517,- 967, filed Jan. 3, 1966,and 531,805, filed Mar. 2, 1966, describes combinations of monoalkyltinsulfides with trisubstituted hindered phenols, and optionally, inaddition, with organotin mercapto carboxylic acids, mercapto carboxylicacid esters, or mercaptides. The purpose of the addition of the phenolis evidently to avoid the deleterious properties of the organotinsulfide, and the further addi tion of the organotin mercaptide, mercaptoacid or mercapto acid ester supplements the effect of the phenol and ofthe organotin sulfide in this regard.

Similar disclosures of polymeric organotin compounds, which generallyinclude a chain of tin atoms connected through oxygen or sulfur atoms,are set out in US. Pats. Nos. 2,597,920, dated Apr. 15, 1962; 2,626,953,dated Jan. 27, 1953; 2,628,211, dated Feb. 10, 1953; 2,746,946, datedMay 22, 1956; 3,184,430, dated May 18, 1965; and 2,938,013, dated May24, 1960.

US. Pat. No. 2,809,956, dated Oct. 15, 1957, discloses polymericorganotin compounds which include mercapto ester groups attached to tin,having the general formula:

wherein SX can be a mercapto; mercapto alcohol or ester;

; or mercapto acid ester group. These compounds, however,

describe a series of thioacetal and thioketal organotin tures were"low-melting solids." The addition or even a small proportion 6fa-liquid'stabilizing additive has unfa'vdfable'etfets on'the heatdistortion temperature and "the impact 'strngthofpolyyinyl chlorideresins. As aresult, it isditficiilty provide a high degree of chemicalstabilityfand a tde'greef of structural "stability, and at the same timecrystal clarity, problems which generally g'of-h'andli'n handwhen rigidresins are subjected to high 'temperatur'econditions. Toattain all ofth'ese"goals, it is necessary to"u'se as s mall an amount of thestabilizer as I, possible, so that the structural strength of there'sinis least carboxylate salt stabilizers which can be prepared in situ bythe reaction of thioacetal and thioketal carboxylic acids withdihydrocarbontin oxides or sulfides or the correspondingmonohydrocarbonor trihydrocarbontiu compounds. 4 z f -According in thepresent invention, a particularly effective polyvinyl chloride resinstabilizer composition is provided having a relatively highconcentration of tin, within the range from about 18 to about 35% Sn,and'a'relatively high concentration of sulfur, within-"the range fromabout 10 to about 25%-S, and comprising an organotinator. B-mercaptocarboxylic acid ester sulfide. 'Theterm .sulfide in this compositionrefersto the' sulfide sulfur group,.-=$, wherein thesulfide-fsulfunvalences are linkedto. the same tin atom or todifierent-tinatoms. Each compound contains per tin atom one or twohydrocarbon or heterocyclic groups linked to tin through carbon, onesulfide sulfur, and at least one aor-fl-mercapto carboxylic acid estergroup. For best results, and to obtain a synergistic stabilizingelfectivenesa at least one of the compounds of the combination of thisinventioncgn;

tains only one hydrocarbon group per tin atom (referred to herein as amonoorganotin compound) and at least one contains two hydrocarbon groupsper tin atom (referred to herein as a diorganotin compound), each by:drocarbon group being linked to tin through a carbon atom. Thiscombination generally improves the initial color of a resin compositionduring heating, i.e., during the first thirty minutes of a heat test,and can also improve the long-term stability before final charring.

The organotin mercapto acid ester sulfides of the invention can bedefined as organotin compounds having organic radicals linked to tinonly through carbon, mercapto sulfur, and sulfide sulfur groups, andhave the general formula:

n is an integer from one to two;

m is the number of COOR groups, and is an integer from one to four;

x is an integer from zero to one;

R is a hydrocarbon radical having from about one to about eighteencarbon atoms, and preferably from four to eight carbon atoms;

R is an organic group derived from a monohydric or polyhydric alcohol ofthe formula R(OH),,,, where n; is an integer from one to about four, butis preferably one or two;

R is R or SZ(COOR Z is a bivalent alkylene radical carrying the S groupin a position alpha or beta to a COOR, group, and can contain additionalfree carboxylic acid, carboxylic ester, or carboxylic acid salt groups,and mercapto groups. The Z radical has from one to about five carbonatoms.

The SZ( COOR groups are derived from monoor poly a and fl-mercaptocarboxylic acid e sters by removal of the hydrogen atom of the mercaptogroup. These include the esters of aliphatic acids which contain atleast one mercapto group, such as, for example, esters of mercaptoaceticacid, aand fi-mercaptopropionic acid, 11- and fl-mercaptobutyric acidand uand fi-mercaptovaleric acid, aand fl-mercaptohexanoic acid,thiomalic acid, aand ,8- mercaptoadipic acid and aand fl-mercaptopimelicacid.

The R hydrocarbon groups can be selected from among alkyl, aryl,cycloalkyl, alkyl cycloalkyl, cycloalkylalkyl, and arylalkyl groupshaving from one to eighteen carbon atoms, and can be the same ordifferent.

The R groups linked to tin through carbon can, for example, be methyl,ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, sec-butyl,amyl, hexyl, octyl, 2-ethylhexyl, isooctyl, dodecyl, palrnityl,myristyl, stearyl, phenyl, benzyl, cumyl, tolyl, xylyl, cyclohexyl,cyclooctyl, cycloheptyl, and cyclopentyl.

R; can be alkl, a'lkylene, alkenyl, aryl, arylene, mixed alkyl,-aryl,mixed aryl-alkyl, cycloaliphatic and heterocyclic, and can contain fromabout one to about twelve carbon atoms, and can also contain estergroups, alkoxy groups, hydroxyl groups, halogen atoms and other inert'substituents. Preferably, R is derived from a monohydric alcoholcontaining from one to about fifteen carbon atoms, such as methyl,ethyl, propyl, s-butyl, n-butyl, t-butyl, isobutyl, octyl, isooctyl,2-ethylhexyl, 2-octyl, decyl, lauryl, cyclic monohydric alochols, suchas cyclopropanol, 2,2dimethyl-l-cyclopropanol, cyclobutanol,2-pheynl-1-cyclo- V pv ene g y ol, cthxl ne y o n pe tylglycota butanol,cyclopentanol, cyclopentenol, cyclohexanol, cy-

nd decamethylene glycol, 2,2,4 -trimethyl pentane-diol, 2,2,4,4-tetramethyl cyclobutanediol, cyclohexane-1,4-dimethaol, and polyolssuch as glycerine, trimethylol ethane, mannitol, sorbitol, erythritol,dipentaerythrito l, pentaerythritol, and trimethylol propane. v

The alcohol R (OH),,, need not be a single-compound. Many of thecommercially available and inexpensive alcohol mixtures are suitable andadvantageous. .The.branched chain primary alcohols made by: the. -Oxo.,process and known as isooctyl, isodecyl and isotridecyl alcohol'fsjkare mixtures of isomers, butcan be used as'if we e'ingle compounds.Other alcohol mixtures that can b'e' used .include mixedhomologousprimaryalcoholsgar ing; from oxidation of the reaction productofethylene'withtriethyl aluminum, isomers and homologous :secondary;alcohols from the hydration of linear C to C olefins or the oxidation oflinear C to C15 ,paraifin s, isomers and homologous straight-chain andmethyl-branched'primary alcohols resulting from the application of the0x0 proeesstoCi, to C linear alpha-olefins, homologous mixtures ofreaction products from ethylene .oxide with alcohols, phenols, orcarboxylic acids, of the proper carbon content and-the like.

It will be evident from the above'that' the organotin mercaptocarboxylic acid ester sulfides of the invention can fall into one of thefollowing genera-l'categories:

R apd 1)m are as defined earlier. R isRorS-Z--(C0OR y is a number fromone to a practical limit Qfifivef Such polymers could b e based on (a)monoalltylit in groups only, having the general formula:

or (b) mixtures of mono iand dialkyl tin groups, having the formula:

practical limit of where p is a number from two to a dive.

Mixtures of A and/or B and/or E with C and "also D or F alone, aresuperior in stabilizing effectiveness to-any of A, B, C and E, takenseparately, and are therefore preferred. v Y

The organotin mercapto acid ester sulfides 'of tlie'iir vention can beprepared by reacting diorganotin halides, monoorganotin halides ormixtures thereof; at a'femp'erature within the range from about 25 toabout-200 C.

with, less than stoichiometric amounts of mercapto car- ,boxylicacidester, in the presence of water or inert organic solventsand an alkalior alkaline metal base such as oxide or hydroxide or tertiary aminebaselin an amount stoic'hiometrically equivalent .to them'ercapto acidester, and th'e'resulting organotin mercapto acid ester halideintermediate can be further reacted with alkali or alkaline earth metalsulfides, such as sodium sulfide, to produce the organotin mercapto acidester sulfide. The following scheme shows the reactions that areinvolved, in the case of monoorganotin compounds (I) anddiorganotincompounds (II).

When n is one the molecular structure corresponds to formula A; when nis two the molecular structure corresponds to formula B. 11

( R, %n-X Hs-z.(oo0R1)m NaOH In the above schemes, X is halide, and n isone or two. Scheme I illustrates the preparation of the monoorganotinmercapto acid ester sulfides, and Scheme II the reaction for thepreparation of diorganotin mercapto acid ester sulfides.

I Alternatively, the monoalkyl tin oxides, stannonic acids, and/ordialkyl tin oxides can be used to prepare the organotin compounds of theinvention. The alkyl tin oxide is reacted with an approximatelystoichiometric amount up to a 25% excess of-dilute mineral acid, suchas, for example hydrochloric acid, at elevated temperatures of fromabout 25 to about 200 C., to form an aqueous solution (in the case ofmonoalkyl tin compounds) or a suspension (in the case of dialkyl tincompounds) of the organotin salt, for example, the chloride in water.The procedureis continued as previously outlined, except that when anexcess of acid is used, it should be neutralized by addition of alkalibefore the alkali or alkaline earth 7 metal sulfide is added. In thesteps of reacting the organotin halide with the organotin mercapto acidester, and of reacting the organotin mercapto acid ester halide withalkali metal or alkaline earth metal sulfide, it is important to takecare that the, pH, of. thefreaction mixture does not exceed about 10,i.e'., become strongly basic, by too rapid addition of alkali.hydroxidebr sulfide, or addition of excess alkali hydroxide or sulfide,since this may result in hydrolysis of the mercapto acid ester. 1

Where the monoorganotin mercapto acid ester sulfide is .being prepared,it will be understood that the product can have the formula shown underA or B, above, or both can exist in admixture, according to the relativeproportion of mercapto acid ester and of sulfide reacted withtheorganotin halide. Compound B has one-half the equivalents ofsulfidesulfur of compound A.

Similiarly, mixed mono and diorganotin compounds of the type of compoundD are obtained by usingmixed monoand diorganotin oxides or halides asstarting materials. When other than stoichiometric proportion oforganotin halide or oxide, mercaptocarboxylic acid ester and/ or alkalisulfide are reacted, polymers are obtained. For example, as the ratio ofmercapto carboxylic acid ester to alkali sulfide is increased from n=1to 11:2 in scheme I, compounds of the type of E are obtained. Othervariations within the generic formula of the invention will be evidentto those skilled in the art from the above description.

It has been indicated previously that synergistic stabilizingefiectiveness is obtained by the use of mixtures of monoorganotin anddiorganotin mercapto acid ester sulfides in accordance with theinvention. The proportions of each can be varied within the range offrom 10 to 90% monoorganotin ester sulfide and from 90 to 10% of thediorganotin ester sulfide, preferably between 20 to and 80 to 20%.Compounds of type D or polymers of type F have a considerably enhancedstabilizing etfectiveness as compared to any of compounds A, B or C, orthe polymer E. Accordingly, mixtures of any of compounds A and/or Band/or E with C, or compounds D or F above, are preferred in accordancewith the invention.

The following organotin mercapto carboxylic acid ester sulfides aretypical of those coming within the invention:

II lstrCqHo-S n-S-CHzC O O CuHa:

(19) [CqHnh- IS n-S-CHg-CHg-COO-CHgCIhO CHzCHzOO CCHnCH;

i [CaHrsh- S n-S-CHa-CHa-COO-CHzCHzO CHzCHqO O CCHzCHz elm-s n-[S c11100 0 08111111 3) n-clrrr s ln-"s-c'mc ooclm h v v "slcrilco'ocrn Cali-1 pspa-1, 5 ccrnooccrns-sn oarr f Specific combinations of or ganotinmercapto carboxylic acid ester sulfides that can be used according tothis invention include the following:

(1) Mono-n-butyltin monoisooctyl thio'glycolat'esulfide-lbis-(din-butyltin monoisooctyl thioglycolate) sulfide. (2)Mono-n-octyltin monocyclohexyl thioglycolate sulfide +bis-(di-n-octyltinmonocylohexyl thioglycolate) sul fide.

(3) Bis-(n-butyltin di-n-butyl thiomalate) sulfide-l-bis- (di-n-butyltinmonoisooctyl thioglycolate) sulfide.

(4) Bis-(n-octyltin di-Z-ethylhexyl betamercaptopropionate)sulfide+bis-(di-n-octyltin monoisooctyl thioglycolate) sulfide.

(5) Bis-(n-octyltin diisooctyl thioglycolate) sulfide+bis-(di-n-octyltin monoisooctyl thioglycolate) sulfide.

(6) n-Octyltin monoisooctyl thioglycolate sulfide+bis- (di-n-butyltinmonoisooctyl thioglycolate) sulfide. V

(7) Cyclohexyltin monoisooctyl thioglycolate sulfide+bis-(dicyclohexyltin .monoisooctyl thioglycolate) sulfide.

(8) Bis-(mono-n-propyltin dicyclohexyl thioglycolate)sulfide+bis-(2-ethylhexyltin mono-Z-ethylbutyl thioglycolate) sulfide.

(9) Bis-(di-n-butyltin mono-2-ethoxyethyl alphamercaptopropionate)sulfide+bis-(isobutyltin 'di-tetrahydrofurfuryl betamercaptopropionate)sulfide.

(10) t-Butyltin mono(methyl thioglycolate) sulfide-l-bis-(diphenyltinmonophenoxyethyl thioglycolate) sulfide.

(11) Ethyltin monoisooctyl thioglycolate sulfide+bis- (dibenzyltinmono-2-ethylhexanoyloxyethyl thioglycolate) sulfide. p, 1

(12) Bis-(isopropyltin di-2,2-dimethylpentyl thioglycolate)sulfide-i-bis-(diisoamyltin mono-Z-octyl. alphamercaptopropionate)sulfide. A

(13) Bis-(n-butyltin dicyclohexyl.thioglycolate)sulfide+bis(di-n-buty1tin monoglyceryl thior glycolate) sulfide. F

The following Examples in the opinion of the inventors representpreferred embodiments of the preparation of organotin mercapto acidester sulfides and'mixt ures thereof in accordance with the invention;

EXAMPLE A Preparation of monobutyltin monoisooctylthioglycolate sulfideTo 70 grams (0.25 mole) of monobutyltin trichloride in 200 ml. of waterwarmed to 50 C. was added S I-Ig'. 0.25 mole) of i sooctylthioglycolate, after which there was slowly added 10 g. (0.25 mole) ofsodium hydroxide dissolved in 15 ml. of Water. The mixture was stirred'for one hour. There was then added 32.5 g. (0.25 mole) of 60% aqueoussodium sulfide, dissolved in ml. of water. The reaction mixture wasextracted with ml. of hexane after stirring for ten minutes, and washedtwice with 150ml. of water.- The hexane was then removed under vacuum. Ayield of 100 g. of monobutyltin monoisooctyl thioglycolate sulfide wasobtained. This corresponds to approximately 97.5% of the theoreticalyield.

The tin content was 28.2% (calculated): 29% and the sulfur content 15.9%(calculated:-15.6%).-

E M Z .B Preparation of bis-(monobutyltin diisooctyl added 20 g. (0.5mole) of sodium hydroxide dissolved in y. htly ti i. he asic side. 11 .2reas qn mixture W 30 ml. of water. The addition of theeNaOI-I wasdropwise, keeping the temperature belowf50 CI The reaction mixture wasstirred for one hour. Next, there was added dropwise 16.25 g. (0.125mole); of 60% aqueous sodium sulfide (dissolved in 50 ml. of-water),keeping the reaction mixture at 50 C. The reaction mixture was thenstirred for one hour at 50 C., cooled below 40 C., and then 150 ml. ofhexane was added. The mixture was stirred for fifteen minutes, and thehexane layer separated, and then washed twice with 150 ml. of water. Theaqueous phases were neutral. The hexane was removed under vacuum at100'"C., recovering 150 g. of product, a 100% yield. The product wasanalyzed and found to contain 20.6% tin (theoretical: 19.9% and 13.1%sulfur (theoretical: 13.4%).

EXAMPLE. 3 Preparation of (monobutyltin diisooctyl thioglycolate)(dibutyltin monoisooctyl thioglycolate) sulfide To-a solution of 70 g.(0.25 mole) of monobutyltin trichloridein 400 ml. of water at" 50 C. inwhich was suspended 75.5 g. (0.25- '-rnole-)- of dibutyltin dichloride,was added-152 .5 g. {0.75 mole) ofisooctyl thioglycolate. 'Next,30g-.--of' sodium'hydroxide"(0.75 mole) in 45 m1. of water'wasaddedslowly, maintaining the temperature 'a't-50 CSStirr ing wascontinued-for one hour. Then 32.5 -*g;= (0.25mole) of 60% Na s dissolvedin 100 ml. water was added slowly and stirred'fo'r-one hour. Then thereaction 'mixturewas cooled'and extracted with 300 ml. of hexane. Thehexane wasrwashed-with water, and then stripped under vacuum at about100 C. The product recovered had a tin content of about 22%(theoretical: 22.5%), and a sulfur content of 12.0% (theoretical:

EXAMPLE D Preparation of bis '(dibutyltin monoisooctyl thioglycolate)sulfide 98.6 g. of concentrated hydrochloric acid and 50 ml. of waterwerewarmed to about 70 C. There was then added' slowly; over a period ofone hour, 124.5 g. of dibutyltin oxide 0.5 mole). The mixture was cooledto 55 C." and 102g. (0:5m'dle) of isooctyl thioglycolate added, followedby the dropwise addition of 20 g. of sodium'hy'droxide (0.5molefdissolved in 30 ml. of water. Next, 32.5 g. 0.25 mole) of sodiumsulfide (60%) dissolved in 90 m1: of wat'eiwas added slowly. The mixturewas stirred at 60 C. for. one; half hour. The product separated frorn'the,.aqueousjsolutiomas a lower layer. The aqueous-upper layerwz'is'decanted, and fresh water added, and the mixture stirred ten minutes at50 C. The water washing was repeated once more. The organic lowerlayer=was separatetgaand.dried,"undervacuum at-80 C. The yield was: 226g.'or'100%'.- The tin content was 26.2%, and the sulfur content 10.5%. P

.?3X TM LB. W Preparation of bis-(monobutyltin diisooctylthioglycolate). sulfide Tof 74 g. of concentrated hydrochloric acid in30ml. of water was added 52.2 g; (0.25 mole)"'of" mono butyl stannonicacid. The reaction mixture was then heated to 65 C., and held at thistemperature for ten minutes. Next, after cooling the reaction mixture to50 C., there was added 102g. (0.5 mole) of isooctyl thioglycolate; and20g. (0.5 mole). of sodium hydroxide (dissolved in 30 extracted with 150ml. of hexane at room temperature, and washed with water until theaqueous layer was neutral. The hexane was thenf stripped off undervacuum at about C. g zercorj product was. .fec'o'vered (97% of thetheoretical). The tin content was 19.5%, and sulfur content 13.5%(calculated: 19.9% Sn, 13.4% S).

EXAMPLE F Preparation of monobutyltin monoisooctyl thioglycolate sulfideTo 74 g. of concentrated hydrochloric acid in 30 ml. of water was added52.25 g. (0.25 mole) of butyl stannonic acid. The reaction mixture wasthen heated to 65 C., and held there for fifteen minutes. After coolingthe mixture to 50 C., there was then added 51 g. (0.25 mole) of isooctylthioglycolate, and 10 g. NaOH (0.25 mole) in 15 m1. dropwise maintainingthe temperature at about 50 C. Next was added 32.5 g. (0.25 mole) of Nas (60%), dissolved in 100 ml. water. The mixture was stirred one hour.The reaction mixture wasextracted with ml. hexane after stirring forfifteen minutes, and washed with 150 ml. water. The hexane was thenremoved under vacuum. A yield of 100 g. of monobutyltin monoisooctylthioglycolate sulfide was obtained. This corresponds to approximately100% of the theoretical yield. The tin content was 29.0% (calculated:29.0%), and the sulfur content 15.3% (calculated: 15.6%).

EXAMPLE G Preparation of a mixture of monobutyltin diisooctylthioglycolate sulfide; bis-(dibutyltin monoisooctyl thioglycolate)sulfide; and (monobutyltin diisooctyl thioglycolate) (dibutyltinmonoisooctyl thioglycolate) sulfide To 148 g. of concentratedhydrochloric acid in 60 ml. of water warmed to 60 C. there was added52.25 g. (0.25 mole) of monobutyl stannonic acid, and the mixture heatedto 65 C. The oxide dissolved slowly. There was then added 93.4 g. (0.375mole) of dibutyltin oxide very slowly over a period of one hour, and thedibutyltin dichloride formed remained suspended in the warm (65 C.)aqueous solution as a melt. 153 g. (0.75 mole) isooctyl thioglycolatewas added slowly, and then 30 g. of sodium hydroxide dissolved in 45 ml.of water was added dropwise, at a rate to maintain the temperature atabout 50 C. without outside application of heat. Next, there was added48.3 g. (0.375 mole) of 60% sodium sulfide (dissolved in 150 ml. ofwater). The addition was dropwise at 50 C. and slight heating wasapplied to maintain this temperature. After 30 minutes at thisten'lperature, addir ib lf pd ns mdp,was-ad edia yftdi 's 1i the reacion and makei iglitly Ba pH 8.300 ml. 'of' xane was added, and sti d." nmi ut the hexane. Them" v/ I v funnel, and the aqueous layer" re oi? ywas then washed with water until neutral, and the hexane finally removedunder vacuum at 100 C. The yieldwas 265 g. of a paleiiyeliow liquid,about 90.5% of the theOreticaL-having a-f-tincontent of 25.0%, and asulfur content"of12.4%. i

,.EXAMPLE H I The procedure of Example C was repeated','; sulistitut'ing 30.2 g. (0.1 mole) of dibutyltin dichloride, 28.0 g. (0.1mole)of monobutyltin trichloride, 51.0 g. (0.25 mole) sodium: sulfide.The product contained. 23.7% ting' arid =Example C wasrepeated,substituting30.2 g. (0.1 mole) (if-"dibutyltindichloride, 14.0g.w(0.05mole)- of monobutyltin trichloride, 51.0 g. (0.25 mole)ofisooctyl thio glycolate, and g. (0.25 mole) -'NaOH, and 6.5 g. (0.05mole) of sodium sulfide. The product that was recovered contained 21.0%tin, and 11.4% sulfur.

EXAMPLE I EXAMPLE K Example C was repeated substituting 48.4 g. (0.16mole) of dibutyltin dichloride, 28.0 g. (0.1 mole) of monobutyltintrichloride, 69.5 g. (0.34 mole) of isooctyl thioglycolate, and 13.6 g.of sodium hydroxide, together with 18.2 g. (0.14 mole) of sodium sulfide(as a 60% aqueous solution). The product recovered had a tin con tent of23.8% and a sulfur content of 12%.

EXAMPLE L The procedure of Example G was repeated, substituting 45.0 g.of monobutyltin oxide, 41.5 g. of dibutyltin oxide, 138 g. of isooctylthioglycolate, 27 g. of sodium hydroxide, and 21.7 g. of sodium sulfide(as a 60% aqueous solution). The product recovered had a tin content of21.9% and a sulfur content of 11.9%.

EXAMPLE M Example G was repeated, substituting 58.8 g. (0.21 mole) ofmonobutyltin trichloride, 24.8 g. (0.1 mole) of dibutyltin oxide,sufficient hydrochloric acid to form the chloride of dibutyltin oxide,143 g. (0.7 mole) of isooctyl thioglycolate, 28 g. of sodium hydroxideand 8.5 g. (0.065 mole) as a 60% aqueous solution of sodium sulfide. Theproduct recovered had a tin content of 18.5% and a sulfur content of11.5%.

The organotin mercapto acid ester sulfides of the invention can be usedas stabilizers with any polyvinyl chloride resin. The term polyvinylchloride as used herein is inclusive of any polymer formed at least inpart of the recurring group x .H t h l and having a chlorine content inexcess of 40%. In this group theX groupscan each beeitherhydrogen orchloririe. ln polyvinyl .chloridevhomopolymers, eachof the X .groupsishydroge'n. Thus, the term includes not, only polyvinyl chloridehomopolymers but also after-chlorinated polyvinyl chlorides such asthose disclosed in British Pat. No. 893,288 and also copolymers of vinylchloride in a major proportion and other copolymerizablemonomers in .aminorproportion, such as copolymers of vinyl chloride and vinyl acetate,copolymers of vinyl chloride with maleic or fumaric acids or esters, andcopolymersof vinyl chloride with styrene, propylene, and ethylene. Theinvention also is applicable to mixtures of polyvinyl chloride in amajor proportion with other synthetic resins such as chlorinatedpolyethylene or a copolymer of .acrylonitrile, 'butadieneand styrene.Among the polyvinyl chlorides which can be stabilized are theuniaXially-stretch oriented 1-2 polyvinyl chlorides describediin'US.Pat. No. 2,984,593 to Isaksernet ,al., that is, syndiotacticpolyvinylchloride, as well as atactic. and isotactic polyvinyl chlorides.

,The organotin mercapto acid ester sulfides of this inveniticiin, bothwith and without supplementary stabilizers, are'exeellent'stabilizersfor both plasticized and unplasticized polyvinylchloride resins. Whe'n'plasticize'r's are to be employed, they may beincorporated in'to the polyvinyl'chloride resins in accordance with'conventional-means. The conventional plasticizers can be used, such" as'dioctyl phthalate, dioctyljsebacate and tricresyl phosphateJWher'e aplasticizer is employed, it can be used in an amount within the rangefrom 0 to parts by weight of the resin. Particularly useful plasticizersare the epoxy higher fatty acid esters having from about twentyto aboutone hundred fifty carbon atoms. Such esters will initially have hadunsaturation in the alcohol or" acid portion'of the molecule, which istaken up by the formation of the epo y group. a

Typical unsaturated acids are oleic, linoleic, linolenic', erucic,ricinoleic and brassidic acids, and these may be esterified with organicmonohydric or polyhydric alcohols, the total number of carbor'i-atomsofthe acid and the alcohol being within the range stated. Typicalmonohydric alcohols include butyl alcohol, 2-ethylhexyl alcohol, laurylalcohol, isooctyl alcohol, st'earyl alcohol, and oleyl alcohol. Theoctyl alcohols are preferred. Typical polyhydric alcohols includepenta'erythritol, glycerol, ethylene glycol, 1,2-propylene glycol,1,4-butylene glycol,"neopentyl glycol, ricinoleyl alcohol, erythritol,mannitol and sorbitol'. Glycerol is preferred. These alcohols may befully or partially esterified with the epoxidized acid. Also useful "arethe epoxidized mixtures of higher fatty acid esters found innaturally-occurring oils such as epoxidized soybean oil, epoxidizedolive oil, epoxidized cottonseed oil, epoxidized tall oil fatty acidesters, epoxidized linseed oil and epoxidized tallow. Of these,epoxidized soybean oil is preferred. The alcohol can contain theepoxy'group and have a long or short chain, and the-acid can havea'shortor long chain, such as epoxy stearyl acetate, epoxy stearyl stearate,glycidyl stearate, andpolym'erized glycidyl' methacrylate. A smallamount, usually not more than 1.5%,of a parting agent or lubricant, alsocan 'be included. Typical parting agents are the higher aliphatic. acidsand salts having twelve to twenty-four carbon atoms, such as stearicacid, lauric acid, palmitic acid and myristic acid, lithium stearate andcalcium palmitate, mineral'lubricating oils, polyvnyl stearate,polyethylene and parafiinwax Impact modifiers, for improving the"toughness or impact-resistance of unplasticized resins, canalso' beadded to the resin compositions'stabilized by the present invention inminor amounts of usually not more than 10%. Examples of such impactmodifiers include chlorinated polyethylene ABS polymers, andpolyacrylate-butadiene graft copolymers. v

The organotin mercapto acid ester sulfide stabilizer'of the invention isemployed in an amount suflicient to impart the desired resistance toheat deterioration at working temperatures of 350 F. and above. Thelonger the time andthe more rigorous the conditions to which the resinwill be subjected during working and mixing, the greater will be theamount required. Generally, as little as 0.25% total of the stabilizerby weight of the resin will improve resistance to heat deterioration.There is no critical upper limit on the amount, but amounts above about10% by weight'of the resin do not give'an increase in'stabilizingeffectiveness commensurate with the additional stabilizer employed.Preferably, the amount: is from about 0.5 to about 5% by weight of theresin. The organotin mercapto acid ester sulfide has a sulfu contentwithin the range from about 10 to about 25%, and a tin content withinthe range from about 10 to 35%. For best results, an overall tin contentfrom about 20% to about 30% by weight is preferred.

13 The stabilizer of the invention is extremely eifective when usedalone, but it can be employed together with other polyvinylchlorideresin stabilizers, but not other organotin compounds, if specialeffects are desired. The stabilizer of .the invention in this event willbe the major stabilizer, and the additional stabilizer will supplementthe stabilizing action of the former, the amount of theorganotin-.estensulfide stabilizer being within the range from about0.25to about 10 parts by weight per 100 parts of the-resin, and theadditional stabilizer being in the amount of from about 0.05 to about 10parts per 100 tium. The non-metallic stabilizers include phosphites,epoxy compounds, phenolic antioxidants, polyhydric alcovhols, and thelike. Epoxy. compounds are especially useful,

and typical compounds are described in US. Pat. No. 2,997,454.

The stabilizers of this invention can be formulated for marketing bymixing the organotin mercapto acid ester sulfide with an inert diluentor with any liquid lubricant or plasticizer in suitable concentrationsready to be added tothe resin composition to give an appropriatestabilizer and lubricant or plasticizer concentration in the resin.Other stabilizers and stabilizer adjuncts can be incorpor'a'tedas well.

The preparation of the polyvinyl chloride resin composition is easilyaccomplished by conventional procedures. The selected stabilizercombination is formed as describ'ed above, and then is blended with thepolyvinyl chlorideresimor alternatively, the components are blendedindividually in the resin, using, for instance, a two or three rollmill, at a temperature at which the mix is fluid and thorough, blendingfacilitated, milling the resin compositionfincluding any plasticizer atfrom 250 to 375 F. for a'time sufiicient to form a homogeneous mass,five minutes, usually. After the mass is uniform, it is sheeted oif inthe usual way.

' For the commercial processing of rigid polyvinyl chloride, thestabilizer is .conveniently mixed with all or a :portionof' the polymerto be stabilized with vigorous agitation under such conditions of timeand temperature resin compositions incorporating the monoand diorganotinmercapto carboxylic acid ester sulfides in accordance with the inventionas stabilizers therefor.

Ingredients: v ,Parts by,weight Polyvinylchloride homopola.

ymer (Diamond 40) 1;00. Acrylonitrile-butadiene sty- 5 renecopolymer;(Ble ndex y I 40 12. Stabilizer To provide 0.40. g. Sn weightas shown in --,,Table I.

The stabilizer concentrations used ineach"sample of resin testedcontained the same total amount of tin, i.e. 0.40 part of tin per 100parts of resin.

The stabilizer was mixed in the resin in the proportion indicated inTable I below on a two roll mill to form a homogeneous sheet, andsheeted off. Strips were cut off from the sheet and heated in an oven at375 F. for two hours to determine heat stability. Pieces of each stripwere removed at minute intervals and aflixed to cards to show theprogressive heat deterioration.

Compounds A-D were used as controls representing the closest prior artstabilizers.

A=Dibutyltin bis(isooctylthioglycolate) B=Monobutyltin tris(isooctylthioglycolate) C=Dibutyltin sulfide D=Butyltin sesquisulfideThe heat degradation is evaluated by the amount of color formed, i.e.,the extent of discoloration relative to the controls. Two scales wereused to characterize the amount of color formation. Scale A covers thecolor range from colorless through tan and amber to greenish brown.Scale B covers the color range from colorless through yellow and orangeto reddish brown. Each scale ranges numerically from 0 (colorless) to 9(brown).

Scale A Scale B Clear and colorless Clear and colorless.

. Touch of yellow. Very pale yellow.

Pale yellow. Yellow. ight amber Yellow-brown edges. 6 Medium dark yellowLight orange brown. 7- Dark amh er Orange brown. 8 Green-brown Reddishbrown. 9- Green-black Brown-black.

The two color scales are necessitated by the fact that organotincompound-stabilized polyvinyl chloride resin formulations do not degradeaccording to a single uniform color scheme. Scale A is applicable to theheat degradation of formulations containing monoorganotin compounds andmixtures of monoorganotin and diorganotin compounds, whereas Scale B isapplicable to formulations containing diorganotin compounds. Theappearance of the samples is reported in Table I below.

TABLE I Example Control A Control B Example 1 Example 2 Example 3Control 0 Control D Example D, Example D, Stabilizer.. A B Example 01.02 1.05 D

Example E, Example F, Amount 2.15 2.65 1.75 0.68 0.45 0.9 0.75

A-O A0 A-O A-O 3-0 11-5 A-l A-O A-l A-l 13-5 A-3 A-B A-l A-l A-l 3-5 A-4A4 A-l A-2 A-2 B-5 A-fi A-4 A-2 A-3 A-3 B-6 A& A4 A-3 A-3 A-4 B-7 A-9A-fi A-4 A-5 A-4 B-8 A-7 A-fi A-7 .A-7 B-9 A-8 A-8 A-8 A-S B-9 EXAMPLES1 TO 3 A series of rigid or nonplasticized formulations was preparedhaving the following composition.

The results clearly indicate the improved efiectiveness of the organotinmercaptoacid ester sulfides of this invention in a rigid polyvinylchloride resin formulation. This 1 is of particular significance becauserigid polyvinyl chloride is known to require the most powerfulstabilizers for effective processing and long term aging.

In Table I, Examples 1, 2 and 3 containing the preferred stabilizercomposition, i.e., a combination of monoand 16 color appearance duringthe first 30 minutes-of heating. In addition, the resin compositions ofExamples 4, ;5 and 6 containing the novel stabilizers underwent :onlylight discoloration even after 60 minutes ofa heating; whereas ControlE, monobutyltin tris(isooctyl.,thio'glycodibutyltin mercapto acid estersulfides, are markedly su- 5 late), acquired a significant discolorationafter *30min-. perior to controls A, 13, C and D. utes of heating, andturned dark green after .60 minutes 1 Example 1 maintains better colorafter 60 minutes of of heating. Controls F and G .were quite'yellow.:ater heating at 375 F. than do controls A, C and D after onlyonly 15 minutes of heating, and became progressively 15 minutes ofheating and control B after 30 minutes of d k on f th heating, 1 1heating. Thisv means for all practical purposes that Examt. I, 1 pie 1has about four times the stabilizing elfectiveness of EXAMPLES 7 AND 1.controls A, C and D, and about two to three times the a effectiveness ofcontrol B. in g gag gg g g fi s pigpa Similarly, Examples 2 and 3 havetwice the effectiveness g g p s l V of control B (the best controlsample). The degree of I di P i by i htdiscoloration reached by thecontrol B after 30 minutes Polyvinyl chloride homo. of heating is notreached by Examples 2 and 3 until 60 polymer (Diamond 40) 100', mlmltesoflleatlflg- Stabilizer To provide 0.41 "tin The particular advantage ofthe stabrhzers of the mvenw g of y tion can better be appreciated if oneconsiders the fact that as shown d ab e the expensive and primarystabilizing ingredient in the 1 controls A through D and Examples 1through 3 (i.e. the tin) is present in equal amounts, 0.40 g. tin phr.,whereas The same procedure was followed in preparing and the totalstabilizer level of Examples 1, 2 and 3 is only testing the resins as inExamples 1 to 3, and theappeare 66%, 64% and 57% of control B,respectively. ance of the test samples is set out in Table IIL; TABLEIII I Example ControlH Controll Examp1e7 Examp1e8 ntrolll i Stabilizer BA Example H Example J o Amount 2.7 2.2 2.2 1.85 1.0

B-O A-O A-O A-O 13-2 A-O A-O A-3 B-3 A-O-l A-O A-3 13-4 A-l A-l A-3-4B-5 A-3 A-2 A-4 13-6 A-5 A-4 B-s B-8 A-8 A-7-8 B-9 B-9 A-9 A-9 1 A-QEXAMPLES 4 TO 6 Another series of resin formulations was prepared havingthe following composition:

Ingredients: Parts by weight Polyvinyl chloride homopolymer (Diamond 40)100 Stabilizer 1.5

The same procedure was followed in praparing and testing thecompositions as in Examples 1 to 3, substituting equal weights ofstabilizers, instead of weights to give equal amounts of tin. Theappearance of the samples is reported in Table II below.

TABLE II Example Control E Control F Example 4 Example 5 Example 6Control G Stabilizer B A Example 11 Example I Example L C A-O A-O A-OA-O A-O A-O A-O A- A-O A-O-l A-O A-4 A-l A-l A-O-l A-5 A-Z A-2 A-Z A-5A-5 A- A-S A-fi A-8 A-S A-9 A-7 .A-9 A-9 A-9 A-8 A-E) .A-9 A-9 A-9 Theresults of-Table H clearly indicate the improved effectiveness obtainedby using mixtures of monoand dibutyltin isooctyl thioglycolate sulfideseven at the low total proportionby weight of 1.5 parts per 100 partsresin. The samples containing the stabilizer of the present invention,Examples 4, 5 and 6, inhibited the deterioration of the resin uponheating at 375 F. for a period of time substantially longer than eithermonobutyltin tris(isoocty1 thioglycolate), 'dibutyltinbis(isooctylthioglycolate) or dibutyltin sulfide, Examples 4, 5 and 6 maintainedbetter 75 heating had begun.

minutes was not reached by the sample of Example 7 until after 45minutes, and by the sample of Example 8 until after minutes of heating.Thus, the stabilizer compositions of this invention considerably extendthe processing period before unacceptable discoloration appears.Controls I, J and K showed undesirable initial color and earlydiscoloration, i.e. ,thedevelopment of a yellow or tan discolorationwithinonly l5 minutes after l f 1so octyl thipglycol};te') or'dib'utyltin sulfide, and thus increaseprocessiflg time before'a harmfuldisooloration ap- 18 EXAMPLES 12 AND 13 Resin compositions were preparedhaving the same formulation as Examples 1 to 3, substituting thestabilizers of Examples E andF. All formulations contained 0.40 g.

The rresults clearly indicategthat when used at equal bentration byweight, the mixed monoand dibiityltiirisooctyl thioglycolate sulfidesinhibit the deteriorapears. Control L acquired a very lightdiscoloration within 15 minutes of heating, but Example 9 did not reachthis discoloration until after 45 minutes of heating, and Example lOonly after 60 minutes of heating. This is equal to three and four timesthe stability of Control L. In addition, Examples 9 and 10 underwentslight discoloration after 75 and 90 minutes of heating at 375 F.,whereas Control-L,* the composition-containing the monobutyltintris(isooctyl thioglycolate), acquired a dark discoloration after;().=1I1in utes, v and was blaek after 75 minutes of heating. Control M,although itdidnot turn black until after two hours of h ea ti-ng,immediately, i.e., after 15 minutes of heating, acquired a yellowdiscoloration, which became progressively-darker on furtherheating,

*EXAMPPELII liesin 'eompositionslwereiprepared having the same .forr'nulation asExamples 1 .to;3, substituting the stabilizer of Example:D', and,the samegtest procedure was followed. 1, The results areloutlinduin Table V. All formulations con- Example ControlA Example 11 ControlBacid sulfide is a b m re; efficient stabilizer than either dibutyltinacid. ester or dibutyltin sulfide.

Example 11' is ea efficient as dibutyltin-bis(isooctyl thioglycolate),Cjiritrol 'A, at ,equal tin levels, though present at onl" 72'% o fftotal stabilizer level, and it is much'be'ttei tn "dibutyl'ti'risulfide,Control C, at equal tin levels. Con rolT'C; i 'ady' :gives severediscoloration at 0.9 phr.,"andfwo v'e 'e ve n more discoloration if usedin larger amountslcompare Controls G and J, Tables The resultsdibutyltin mercapto Ingredients: f Parts by weight Polyvinyl chloridehoniopolymer (Diamond 5 tm 40) v The same test procedure was followedand the results lsooctyl epoxy stearate. 3 are tabulated in Table VI-Stabilizer 2.2 TABLE IV .11. Example ControlB Example 12 Example 13Conn-01D 'Ihe jsa me pr ur 'wasfollowed 1n preparing and test- 10 S H BE 1 E E 1 F D "'ing'tlie compositions "as" in Examples 1 to 3, and theaptab xampe xampe pearance of the samples is reported in Table IV below.2.02 1.35 0.75 r: r: is Example Control]. Examples} Example 10 ControlMii-3 xii-3 Stabilizer B ExampleJ ExampleK o A-4 A-5 A-8 A-4 A-G A-e A-OA0 A4) A4) f2 A 9 A-9 1 i12 Is 20 Examples 12 and 13 demonstrate theadvantage of the A ii if; monobutyltin mercapto acid ester sulfides overeither the 4 A-3 A-fi monobutyltin mercapto acid esters or themonobutyltin ig- 2:1 sulfides alone.

Examples 12 and 13 have better color stability after 30 minutes ofheating than the monobutyltin tris(isooctyl thioglycolate), Control B,and monobutyltin sulfide, Control D at equal tin content, and this isonly 76.5% and 57% of total stabilizer level of Control B. Control Dalready had severe discoloration after 15 minutes, at equal tin content,and would only provide greater discoloration at higher concentrations.

The stabilizer compositions of this invention are advantageously used inresins formed into many useful structural members including extrudedpolyvinyl chloride pipe useful for water, brine, crude petroleum,gasoline, natural and manufactured fuel gas, and domestic and industrialwastes; flat and corrugated profiles for the construction industry, andblow-molded bottles. Typical formulations are as follows:

Pipe:

Composition: Parts by weight Medium mol. wt. polyvinyl chloridehomopolymer (K=55) 100 ABS polymer 10 Calcium stearate 1 Product ofExample I 1.4 Pigment As desired Parisons for blow-molding bottles:

Composition:

Medium mol. wt. polyvinyl chloride homopolymer (K=55) 100Styrene-butadiene-methyl methacrylate polymer 10 Stearic acid 0.5Product of Example L 1.6 Blue dye 0.0005-0.002 Food-grade bottles:

Composition:

Medium mol. wt. polyvinyl chloride homopolymer (K=55) 100 ABS polymer 10n-Octyltin isooctyl thioglycolate sulfide 0.9 Bis(di-n-octyltinmonoisooctyl thioglycolate) sulfide Di- -ccty noxi e --a.. 0.05.,Profilel's;

Composition; l

I, High mol. wt. polyvinyl chloride 9.- a -,.l,Po1ymerY(K.- ,70) f .100'l Chl'jorinated polyethylene (31% Cl) 15 l sooctyl epoxystearate- 2Di-n-octyltin bis(monoisooctyl thioglycolatel sulfide 1.0 n-Butyltinisooctyl thioglycolate sulfide 0.55 Magnesium stearate -lI.. I.. 0.25

These formulations each contain sufiicient stabilizer in accordance withthe invention to be processed at elevated temperatures into the desiredshapes without deleterious discoloration or embrittlement.

Having regard to the foregoing disclosure, the following is claimed asthe inventive and patentable embodiments thereof:

1. A halogen-containing polymer selected from the group consisting ofhomopolymers and copolymers of vinyl chloride and chlorinated polymersof vinyl chloride and a stabilizing amount of a compound of the formulaA Jr RX 11 (3-n) wherein R and R are hydrocarbon groups which may be thesame or different and which are selected from the group consisting ofalkyl, aryl, cycloalkyl, alkylcycloalkyl and arylalkyl groups havingfrom one to eighteen carbon atoms each, X is' the radical --SZ(COORwherein R is an organic group derived from a monohydric or polyhydricalcohol having from one to about four hydroxyl groups and from one toabout eighteen carbon atoms, Z is a bivalent alkylene radical carryingthe S group in a position alpha or beta to the COOR group, having fromone to five carbon atoms and optionally containing additional groupsselected from free carboxylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups and mercapto groups, the organotin compoundhaving an amount of tin within the range from about 18 to about 35% byweight and an amount of sulfur within the range from about to about 25%by weight, m is an integer from one to four and n is an integer of 1 or2.

2. The halogen-containing polymer of claim 1, wherein said stabilizer isa compound of the formula 3. The halogen-containing polymer of claim 1,wherein said stabilizer is a compound of the formula 4. A polyvinylchloride resin composition having an enhanced resistance todeterioration when heated at 350 'F., comprising a polyvinyl chlorideresin and an organotin mercapto carboxylic acid ester sulfide having theformula:

n is an integer from one to two,

x is zero or one,

m is the number of COOR groups, and is an integer from one to four,

[R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkyl, alkyl and arylalkylgroups and having from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms,

R is R or SZ(COOR and Z is a bivalent alkylene radical carrying the Sgroup in a position alpha or beta to a COOR group, having from one toabout five carbon atoms, and optionally containing additional groupsselected from free carboxylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups, and mercapto groups,

20 the organotin compound having an amount of tin within the range fromabout 18 to about 35% by weight, and an amount of sulfur within therange from about 10 to about 25% by weight.

5. A polyvinyl chloride resin composition in accordance with claim 4, inwhich the polyvinyl chloride resin is polyvinyl chloride homopolymer.

6. A polyvinyl chloride resin composition in accordance with claim 4, inwhich the polyvinyl chloride resin is a copolymer of a major quantity ofvinyl chloride and a minor quantity of another vinyl monomer. v

7. A polyvinyl chloride resin composition in accordance with claim 4, inwhich the amount of stabilizer composition is within the range fromabout 0.25% to about 10 %by weight of the composition.

8. A polyvinyl chloride resin composition in accord: ance with claim 4,including in addition a polyvalent metal salt of a carboxylic acid oralkyl phenol.

9. A polyvinyl chloride resin composition in accordance with claim 4,including in addition an epoxy compound.

10. A polyvinyl chloride resin composition in accordance with claim 4,including in addition a plasticizer for the the resin in an amount inexcess of about 10% by weight.

11. A rigid polyvinyl chloride resin composition in acordance with claim4, comprising a plasticizer in an amount up to about 10% by weight ofthe composition.

12. A polyvinyl chloride resin composition in accordance with claim 4,including in addition a phenolic antioxidant.

13. A polyvinyl chloride resin composition in accordance with claim 4,including in addition an impact modifier.

14. A mixture of organotin mercapto carboxylic acid ester sulfidesuseful as a stabilizer for improving the resistance to deterioration ofpolyvinyl chloride resins when heated at 350 F., and having at least onetin atom to which organic groups are linked only through carbon andsulfur, having linked to tin through sulfur of a mercapto group at leastone alphaor beta-mercaptocarboxylic acid ester group, and having atleast one sulfide sulfur group; one of said organotin mercaptocarboxylic acid ester sulfides having one hydrocarbon group linked totin through carbon, and one of said organotin mercapto carboxylic acidester sulfides having two hydrocarbon groups linked to tin throughcarbon, the organotin mercapto carboxylic acid ester sulfides each beingselected from the class having the formula:

n is an integer from one to two,

x is zero or one,

m is the number of COOR groups, and is an integer from one to four,

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkyl, alkyl and arylalkylgroups and having from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms, 7

R is R or S-Z-(COOR and Z is a bivalent alkylene radical carrying the Sgroup in a position alpha or beta to a COOR group, having from one toabout five carbon atoms, and optionally containing additional groupsselected from free carboxylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups, and mercapto groups, the organotin mercaptocarboxylic acid ester sulfides.

wherein 21 having an amount of tin within the range from about 18 toabout% byweighr; andananiountoffsulfur within the=- range from about '10toabout 25% "-by-- weight.

15. A mixture of organotin mercapto carboxylic acid 5 ester sulfides inaccordance with claim 14,"in which the organotin mercapto carboxylicacid ester sulfide-having one hydrocarbon group has the formula:

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and arylalkyl groupsand having from about one to about eighteen carbon atoms,

[R is an organic group derived from a monohydric or 0polyhy'clricalcohol' having from one to about four 'hydroxylgroups andfrom one to about eighteen carbon.atoms, and

is a bivalent alkylene radical carrying the S group in ""ap'asiaofial haor beta toa COOR group, having from one to about five carbon atoms, andoptionally 1 containing additional groups selected from free carboxylicacid groups, c'arboxylic acid ester groups, carboxylic acid salt groups,and mercapto groups,

wherein m is the number of COOR, groups, and is an integer from one tofour, R is'a hydrocarbon group selected from the group -consisting ofalkyl, aryl; cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and aralkylgroups and 51 having from about one-to about eighteen carbon 5 R, is anorganic group derived from a monohydric .7 V t orpolyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteer'rcarbon "atoms, and Z is a bivalent alkylene radical carryingthe S group iira position alpha or beta to a COOR group, having from oneto about five carbon atoms, and optionally containing additional groupsselected from free carboxylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups, and mercapto groups.

16. A mixture of organotin mercapto carboxylic acid ester sulfides inaccordance with claim 14, in which the organotin mercapto carboxylicacid ester sulfide having one hydrocarbon group has the formula?- 00R;groups, and is an integer m is the number of C from one to four,

R is a hydrocarbon group selected fromthe group consisting of alkyl,aryl, cycloalkyl, alkylcyc-loalkyl, cycloalkylalkyl and arylalkyl groupsandhaving from about one to about eighteen carbon atoms,

R is an organic group derived from amonohydric or 22 I 1 hydroxylgroupsand from one to about eighteen carbonatoms,and Z is a bivalent-alkyleneradical carrying the S group 7, v in a position alpha or beta to a COORgroup, having from one to about five carbon atoms, and optionallycontaining additional groups selected from free carboxylic acid groups,carboxylicacid salt groups, carboxylic acid ester groups, and mercaptogroups, and the organotin mercapto carboxylic acid ester sulfide havingtwo hydrocarbon groups has the formula: I

(Rh-n-S-Z-(C O OROm wherein m is the number of COOR groups, and is aninteger from one to four,

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and aralkyl groupsand having from one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms, and

Z is a bivalent alkylene radical carrying the S group in a positionalpha or beta to a COOR group, having from one to about five carbonatoms, and optionally containing additional groups selected from freecarboxylic acid groups, carboxylic acid ester groups, carboxylic acidsalt groups, and mercapto groups.

17. A mixture of organotin stabilizers in accordance with claim 14,wherein the hydrocarbon groups in the organotin mercapto carboxylic acidester sulfides are each alkyl, and the mercapto carboxylic acid estergroups are each alkyl esters of a mercapto carboxylic acid having fromtwo to five carbon atoms, the alkyls having from one to eighteen carbonatoms.

18. A mixture of organotin mercapto carboxylic acid ester sulfides inaccordance with claim 17, wherein the hydrocarbon groups are butyl, andthe mercapto carboxylic acid ester group is a thioglycolate ester.

19. A mixture of organotin mercapto carboxylic acid ester sulfides inaccordance with claim 17, wherein the hydrocarbon groups are octyl, andthe mercapto carboxylic acid ester group is an octyl ester of a mercaptocarboxylic acid having from two to five carbon atoms.

20. A mixture of organotin mercapto carboxylic acid ester sulfides inaccordance with claim 17, wherein the hydrocarbon groups are butyl, andthe mercapto carboxylic acid ester group is a butyl ester of a mercaptocarboxylic acid having from two to five carbon atoms.

21. A polyvinyl chloride resin composition in accordance with claim 4wherein the hydrocarbon group in the I organotin mercapto carboxylicacid ester sulfide is alkyl,

' butyl, and the mercapto carboxylic acid ester group is a thioglycolateester.

23. A polyvinyl chloride resin composition in accordance with claim 21,wherein the hydrocarbon group is octyl, and the mercapto carboxylic acidester group is an octyl ester of a mercapto carboxylic acid having fromtwo to five carbon atoms. I

24. A polyvinyl chloride resin composition in accordance with claim 21,wherein the hydrocarbon groups are butyl, and the mercapto carboxylicacid ester group is a 23 butyl ester of amercapto carboxylic acid havingfrom two to five carbon atoms.

25. A polyvinyl chloride resin composition having an enhanced resistanceto deterioration when heated at 350 F., comprising a polyvinyl chlorideresin and a mixture of organotin mercapto carboxylic acid ester sulfidesin accordance with claim 14.

26. A polyvinyl chloride resin composition having an enhanced resistanceto deterioration when heated at 350 F., comprising a polyvinyl chlorideresin and a mixture of organotin mercapto carboxylic acid ester sulfidesin accordance with claim 15.

27. A polyvinyl chloride resin composition having an enhanced resistanceto deterioration when heated at 350 F., comprising a polyvinyl chlorideresin and a mixture of organotin mercapto carboxylic acid ester sulfidesin accordance with claim 16.

28. A polyvinyl chloride resin composition in accordance with claim 4wherein the organotin mercapto carboxylic acid ester sulfide has theformula:

n is an integer of one, .x is an integer of one, and m is the number ofCOOR groups, and is an integer from one to four. 29. A polyvinylchloride resin composition in accordance with claim 4, wherein theorganotin mercapto carboxylic acid ester sulfide has the formula:

wherein wherein m is the number of COOR groups, and is an integer fromone to four,

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and arylalkyl groupsand having from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms, and

Z is a bivalent alkylene radical carrying the S group in a positionalpha or beta to a COOR group, having from one to about five carbonatoms, and optionally containing additional groups selected from freecarboxylic acid groups, carboxylic acid ester groups, carboxylic acidsalt groups, and mercapto groups.

30. A polyvinyl chloride resin composition in accordance with claim 4,wherein the organotin mercapto carboxylic acid ester sulfide has theformula:

wherein m is the number of COOR; groups, and is an integer from one tofour,

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and arylalkyl groupsand having from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms, and

ance with claim 4, in which the organotin mercaptocar;

boxylic acid ester sulfide has the formula:

(Rz) Sns-Z(COOI 1)m m is the number of COOR groups, and is an integerfrom one to four, j j

R is a hydrocarbon group selected from the groupconsisting of alkyl,aryl, cycloalkyl, alkycycloalkyl, cycloalkylalkyl and aralkyl groups andhaving from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and'from one to abouteighteen carbon atoms, and v Z is a bivalent alkylene radicalcarryingthe S group in a position alpha or beta to a COOR group, having from oneto about five carbon atoms, and optionally containing additional groupsselected from free carboXylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups, and mercapto groups.

32. A polyvinyl chloride resin composition in accordance with claim 4,wherein the organotin mercapto carboxylic acid ester sulfide has theformula:

wherein m is the number of COOR groups, and is an integer from one tofour,

R is a hydrocarbon group selected from the group consisting of alkyl,aryl, cycloalkyl, alkylcycloalkyl, cycloalkylalkyl and aralkyl groupsand having from about one to about eighteen carbon atoms,

R is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms and Z is a bivalent alkylene radical carrying theS group in a position alpha or beta to a COOR group, having from one toabout five carbon atoms, and optionally containing additional groupsselected from free carboxylic acid groups, carboxylic acid ester groups,carboxylic acid salt groups, and mercapto groups.

33. A polyvinyl chloride resin composition having an enhanced resistanceto deterioration when heated at 350 F. comprising a polyvinyl chlorideresin and an organotin mercapto carboxylic acid ester sulfide which hasthe formula:

is an integer 25 cloalkylalkyl and aralkyl groups and having from aboutone to about eighteen carbon atoms,

R, is an organic group derived from a monohydric or polyhydric alcoholhaving from one to about four hydroxyl groups and from one to abouteighteen carbon atoms, R is R or S-Z(COOR and Z is a bivalent alkyleneradical carrying the S group in a position alpha or beta to a COORgroup, having from one to about five carbon atoms, and optionallycontaining additional groups selected from free carboxylic acid groups,carboxylic acid ester groups, carboxylic acid salt groups, and mercaptogroups.

References Cited UNITED STATES PATENTS DONALD E. CZAJA, Primary ExaminerV.P. HOKE, Assistant Examiner UNITED STATES PATENT OFF ICE Page I of PPatent No.

Dated June 18, 1974 Iwent fl Otto S. Kauder et 211 t is certified thaterror appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

F:I o 1umn 1, line 61 Column 2, line 49 Column 3, line 39 Column 3, line5'? Column 3, line 67 Column 4, lines 3-4 Column 4, line 47 Column 4,line 61 'difficulty" should be difficult- "organo in" should be organotin'-- e sters" should be -esters alkl" should be -alkyl "pheynl"should be phenyl-- "dimethaol" should be --dimethanol-' (F) 1i n i I. IV n S lm-R l should be n-I Z I I I I I II I n S 11-11 I II I I-Z-(COORDJ; -(COOR|)= J Page 2 of l Patent 2Z0. 3,817,915,

Dated June 18,

lnveni o' -(g) S. Kauder et a1 It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

r.- Column '7, line 7 Column 7, line 45 Column 8, line 1 Column 12, linel9 ISO-04H,

tHaOOCCHr-S- n-- SO-(T ny '1 I S-Sn somooooang I somooocun lcanooccrw-s-h- CHaCOOCcH 4 should be (10) mom should be "monocylohexyl"should bemonocyclohexyl "polyvnyl" should be -po'lyvinylr- Column 15,line 48 Page A of I- UNITED STATES PA'IEN'I' OFFICE CERTIFICATE OFCORRECTION Patent No.

Dated June 18, 1974 Inventor(s) It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

"praparing" should be -preparing- 7 Column 17, line 15 Table IV "control1" should be --control L Column 18, line 11 Table IV "stablizer shouldbe .stabilizer- Column 20, line 27 "acordance" should be accordanceo H vH Column 23, hne 63 should be Signed and Sealed this ninth Day Of March1976 [SEAL] Arrest:

RUTH C. MASON Arresting Officer C. MARSHALL DANN Commissioner ofPatentsand Trademarks

